The invention is generally directed to toner and developer compositions, and more specifically, the present invention is directed to developer and toner compositions containing a mixture of certain pigments and optional charge enhancing additives, which impart or assist in imparting a triboelectric charge to the toner resin policies and enable toners with rapid admix characteristics. In embodiments, there are provided in accordance with the present invention toner compositions comprised of resin policies, first pigment policies of Pigment Red 81:3 (C.I #45160:3 which is a molybdate silicate salt of Rhodamine), and second pigment policies of a metal free pigment like Pigment Red 122 (C.I. #73915, 2,9-dimethylquinacridone). More specifically, the first pigment is present in an important amount of from about 0.5 to about 1.2 and preferably about 1 weight percent, and the second pigment is present in an amount of from about 1.5 to about 10.2 and preferably from about 1.8 to about 7.9 weight percent, with the exact amount, or concentration determined by the average mass per unit area of the image developed in the xerographic printing process. Advantages associated with the toners of the present invention include more precise control of the toner triboelectric characteristics, and the use of less pigment which contains the metal molybdenum, which metal can be considered hazardous, while maintaining substantially all of the color characteristics of Pigment Red 81:3. Thus, far example, by reducing the amount of FANAL PINK.RTM., which is a Pigment Red 83:1 and a current commercial toner magenta pigment, California waste disposal requirements will be satisfied it is believed. In embodiments, the amount of FANAL PINK.RTM. selected, which also functions as a toner positive charge enhancing additive, can be reduced by almost two thirds. The aforementioned toners in embodiments of the present invention enable, for example, toners with rapid admix of less than about 15 seconds, and more specifically, from about 1 to about 15 seconds in embodiments, extended developer life, stable electrical properties, high image print quality with substantially no background deposits, brilliant magenta color, and compatibility with fuser rolls including VITON.RTM. fuser rolls. The toner compositions of the present invention in embodiments thereof possess excellent admix characteristics as indicated herein, and maintain their triboelectric charging characteristics for an extended number of imaging cycles exceeding, for example, 1,000,000 in a number of embodiments. The toner and developer compositions of the present invention can be selected for electrophotographic, especially xerographic, imaging and printing processes, including color processes.
Toner compositions with pigments such as FANAL PINK.RTM. or HOSTAPERM PINK.RTM. are known. However, these toners possess disadvantages, such as poor to acceptable tribo after extended use, and the amount of metal, about 0.89 to 1.49 percent molybdenum, present in the toner and originating from the FANAL PINK.RTM. does not, it is believed, meet California waste disposal requirements. HOSTAPERM PINK.TM. (Pigment Red 122) alone has a poor magenta color when compared to a FANAL PINK.RTM. (Pigment Red 81:3) containing toner. These and other disadvantages are avoided or minimized with the toners of the present invention.
Encompassed within the scope of the present invention are colored toner and developer compositions comprised of toner resin particles, optional carrier particles, the charge enhancing additives illustrated herein, and as pigments or colorants magenta particles, or mixtures thereof, which toners and developers useful with other process colors such as cyan toner and yellow toners. More specifically, with regard to the generation of color images utilizing the toner and developer composition illustrative, examples of magenta materials that may be selected as pigments include, for example, Pigment Red 81:3 and Pigment Red 122. Illustrative examples of cyan materials that may be used as pigments include copper tetra-4-(octadecyl sulfonamido)phthalocyanine, X-copper phthalocyanine pigment listed in the Color Index as CI 74160, CI Pigment Blue, and Anthrathrene Blue, identified in the Color Index as CI 69810, Special Blue X-2137, and the like; while illustrative examples of yellow pigments that may be selected are diarylide yellow 3,3-dichlorobenzidene acetoacetanilides, a monoazo pigment identified in the Color Index as CI 12700, CI Solvent Yellow 16, a nitrophenyl amine sulfonamide identified in the Color Index as Foron Yellow SE/GLN, CI Dispersed Yellow 33, 2,5-dimethoxy-4-sulfonanilide phenylazo-4'-chloro-2,5-dimethoxy acetoacetanilide, Permanent Yellow FGL, and Pigment Yellow 185. The aforementioned pigments are incorporated into the toner composition in various suitable effective amounts as illustrated herein.
Toner and developer compositions with charge enhancing additives, which impart a triboelectric positive or negative charge to the toner resin, are known. Thus, for example, there is described in U.S. Pat. No. 3,893,935 the use of quaternary ammonium salts as charge control agents for electrostatic toner compositions. In this patent, there are disclosed quaternary ammonium compounds with four R substituents on the nitrogen atom, which substituents represent an aliphatic hydrocarbon group having 7 or less, and preferably about 3 to about 7 carbon atoms, including straight and branch chain aliphatic hydrocarbon atoms, and wherein X represents. an anionic function including, according to this patent, a variety of conventional anionic moieties, such as halides, phosphates, acetates, nitrates, benzoates, methylsulfates, perchloride, tetrafluoroborate, benzene sulfonate, and the like; U.S. Pat. No. 4,221,856 which discloses electrophotographic toners containing resin compatible quaternary ammonium compounds in which at least two R radicals are hydrocarbons having from 8 to about 22 carbon atoms, and each other R is a hydrogen or hydrocarbon radical with from 1 to about 8 carbon atoms, and A is an anion, for example sulfate, sulfonate, nitrate, borate, chlorate, and the halogens such as iodide, chloride and bromide, reference the Abstract of the Disclosure and Column 3; a similar teaching is presented in U.S. Pat. No. 4,312,933 which is a division of U.S. Pat. No. 4,291,111; and similar teachings are presented in U.S. Pat. No. 4,291,112 wherein A is an anion including, for example, sulfate, sulfonate, nitrate, borate, chlorate, and the halogens. There are also described in U.S. Pat. No. 2,986,521 reversal developer compositions comprised of toner resin particles coated with finely divided colloidal silica. According to the disclosure of this patent, the development of electrostatic latent images on negatively charged surfaces is accomplished by applying a developer composition having a positively charged triboelectric relationship with respect to the colloidal silica.
Also, there are disclosed in U.S. Pat. No. 4,338,390, the disclosure of which is totally incorporated herein by reference, developer compositions containing as charge enhancing additives organic sulfate and sulfonates, which additives can impart a positive charge to the toner composition. Further, there are disclosed in U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions with resin particles and pigment particles, and as charge enhancing additives alkyl pyridinium compounds. Additionally, other documents disclosing positively charged toner compositions with charge control additives include U.S. Pat. Nos. 3,944,493; 4,007,293; 4,079,014; 4,394,430, and 4,560,635 which illustrates a toner with a distearyl dimethyl ammonium methyl sulfate charge additive. One disadvantage associated with the charge additive of the '635 patent resides in its apparent inherent instability in some instances, thus rendering it substantially unsuitable as a bulk toner constituent in imaging processes, as the additive can thermally and chemically degrade, and react with other toner components.
Moreover, toner compositions with negative charge enhancing additives are known, reference for example U.S. Pat. Nos. 4,411,974 and 4,206,064, the disclosures of which are totally incorporated herein by reference. The '974 patent discloses negatively charged toner compositions comprised of resin particles, pigment particles, and as a charge enhancing additive ortho-halo phenyl carboxylic acids. Similarly, there are disclosed in the '064 patent toner compositions with chromium, cobalt, and nickel complexes of salicylic acid as negative charge enhancing additives. Also, toners with negative charge additives are illustrated in U.S. Pat. Nos. 4,845,003; 4,758,493; 4,433,040; 5,223,368 and 5,324,613, the disclosures of which are totally incorporated herein by reference. These additives, such as the ALOHAS, an aluminum salt of substituted carboxylic acid, of the latter two patents, can be selected as charge enhancing agents for the toners of the present invention.
in some of the aforementioned patents and other patents, toners with certain colored pigments of magenta, cyan, yellow, green, blue, red, brown, and mixtures thereof are disclosed.
Rhodamines are illustrated in copending application U.S. Ser. No. 331,444, now U.S. Pat. No. 5,486,443 the disclosure of which is totally incorporated herein by reference.